This invention relates to internal combustion engines and more particularly to engines in which stratified charges of segregated rich and lean air-fuel mixtures are formed in the engine combustion chambers.
It is known in the art to provide internal combustion engines with means for forming segregated or stratified mixtures of different mixture strengths within an open combustion chamber. Some success in forming mixtures of this type has been obtained by using direct injection of atomized liquid fuel into a swirling mass of air adjacent to, or upstream of, the spark plug location.
To avoid the problems of direct fuel injection, other proposals have been made to utilize separate or divided inlet passages to direct the rich and lean mixtures to different portions of the engine combustion chamber. I have found, however, that where development of a swirling stratified charge is attempted by simultaneous admission of rich and lean mixtures through separate or divided passages, the resistance to flow of residual gases in the cylinder causes a partial mixing of the rich and lean mixtures before a suitable vortex or swirling flow pattern has been generated, thus reducing the degree in which stratified charge combustion is realized.